<!DOCTYPE html>
<html>
<head>
<meta content="charset=utf-8" />
</head>

<body>
<?php
define('APP_SECRET', 'ae10764256f0aed81aa39d810ee07e3a');
// No need to change the function body
function parse_signed_request($signed_request, $secret) 
{
list($encoded_sig, $payload) = explode('.', $signed_request, 2);
// decode the data
$sig = base64_url_decode($encoded_sig);
$data = json_decode(base64_url_decode($payload), true);
if (strtoupper($data['algorithm']) !== 'HMAC-SHA256')
{
error_log('Unknown algorithm. Expected HMAC-SHA256');
return null;
}

// check sig
$expected_sig = hash_hmac('sha256', $payload, $secret, $raw = true);
if ($sig !== $expected_sig) 
{
error_log('Bad Signed JSON signature!');
return null;
}
return $data;
}
function base64_url_decode($input) 
{
return base64_decode(strtr($input, '-_', '+/'));
}
if ($_REQUEST) 
{
$response = parse_signed_request($_REQUEST['signed_request'],
APP_SECRET);

$name = $response["registration"]["name"];
$email = $response["registration"]["email"];
$password = $response["registration"]["password"];
$gender = $response["registration"]["gender"];
$dob = $response["registration"]["birthday"];

echo $name;
echo "<br/>".$email;
}?>

</body>
</html>
